1. Technical Field
The invention relates to the field of controlling a data source which generates a data stream that is received by two or more components of a communications network. In particular, the invention relates to aspects in context with conferring control of the data source among the individual network components.
2. Description of the Prior Art
Due to increasing capacities of modern wire-line and wireless communications networks, novel network applications like real-time teleconferencing or collective video-on-demand have become feasible. Such conference-like network application require the management of interaction among the individual participating network components.
A typical scenario which requires the management of interaction is a streaming session during which two or more network components receive a data stream from a streaming source like a multimedia server. Various protocols for controlling a streaming session are known in the art. As an example the Real Time Streaming Protocol, or RTSP, specified in the Internet Engineering Task Force (IETF) document RFC 2326; Real Time Streaming Protocol (RTSP); April 1998 can be mentioned. RTSP is an application-level protocol for controlling the delivery of data with real-time properties such as audio and video data. Sources of data can comprise live data feeds and stored clips. Session control according to RTSP includes both setting up and controlling the data stream so that RTSP can be visualized as a “network remote control” for multimedia servers.
When a streaming session has been set up, individual network components may be invited to participate in the streaming session. This process is exemplarily described in chapter 16.2 “Invitation to a Multicast Conference” of the IETF document RFC 2543; SIP: Session Initiation Protocol; March 1999.
According to SIP, only the initiator of a session controls the session. Further network components participating in the session have a passive role. This might lead to the situation that a specific session gets out of control if the session initiator can or does not control the session any longer. Furthermore, the session always has to be terminated when the session initiator wishes to leave the session.
There is a need for an improved control mechanism for scenarios in which a plurality of network components participate in the session. Furthermore, there is a need for hardware components implementing such a control mechanism and a user interface appropriately configured to operate such a control mechanism.